I love the flat screen idea. I buy and rent, but I would put a flat screen over the fireplace if I were flipping. It saves space so the living room is bigger. Black Friday...good time.
That said, nickle hinges, door knobs and light fixtures really look nice. They're at eye level. I had to change out the outlets on my last house because they had been painted over multiple times (what the hell?) and it wasn't cheap--materials were. Changing the plates would be a no brainer with painting.
If my flips were taking too long to sell, I would take a page from the builder model homes. They try to make the homes memorable. Beige with white trim is so common, I would paint an accent wall in the living; or paint the kitchen "Pottery Barn" sage or the hall bath pale metallic silver with a shimmery, trendy shower curtain. Cheap, easy enough for buyers to change, but the right colors will appeal to alot of buyers. (Unfortunately, I don't have "the right colors", but at HD I found a beautiful Martha Stewart green that almost looks beige in indirect light. I used it once and plan on using it again.)